Deadliest Tornado Outbreak

Source: National Weather Service

The most expensive tornado outbreak in U.S. history and the deadliest of the year occurred May 3–4, 1999, in Oklahoma and Kansas. In less than 21 hours, a total of 74 tornadoes touched down across the two states, with as many as four tornadoes from different storms on the ground at once.

An F-5 tornado, the strongest on the Fujita Tornado Scale, moved along a 38-mi. (61-km) path, from Chickasha through south Oklahoma City and the suburbs of Bridge Creek, Newcastle, Moore, Midwest City, and Del City. With 8,000 buildings damaged, the Oklahoma City tornado is the most expensive single tornado in history, causing about a billion dollars in damage. In all, the tornadoes killed 46 people, injured 800, and caused $1.5 billion in damage.

The deadliest and most devastating U.S. tornado outbreak of the 20th century was the April 3–4, 1974, “Super Tornado Outbreak.” It lasted 16 hours and produced a total of 148 tornadoes across 13 states, killing 330 people and injuring more than 5,000.